In order to meet the demand for wireless data traffic which has increased since the commercialization of the fourth Generation (4G) communication system, efforts have been made to develop an improved fifth Generation (5G) communication system or a pre-5G communication system. For this reason, the 5G or pre-5G communication system is called a “beyond 4G network communication system” or a “post long-term evolution (LTE) communication system.”
In order to achieve a high data transfer rate, the 5G communication system is considered to be implemented in an ultra-high frequency (millimeter Wave (mmWave)) band (e.g., 60 GHz band). In order to reduce the path loss of radio waves and increase the transmission distance thereof in the mmWave band, techniques, such as beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large scale antenna, are under discussion in the 5G communication system.
Also, in order to improve a network of a system, the development of techniques, such as evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), and reception interference cancellation, has been conducted in the 5G communication system.
In addition, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and sliding window superposition coding (SWSC), which are advanced coding modulation (ACM) schemes; and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA), which are advanced access techniques, have been developed in the 5G system.
Since various attempts have been made to apply the 5G communication system to an Internet of Things (IoT) network, channel coding is required which supports not only a high data transfer rate but also a low data transfer rate. Accordingly, an LDPC code, which can operate with low power (areal efficiency) which is four times lower than or is more than four times lower than that of a turbo code, is considered as a representative next-generation error correction technique.
The LDCP code to be applied in the 5G system needs to support not only a high data transfer rate but also a low data transfer rate, and thus uses a parity check matrix (PCM) having a low coding rate. Accordingly, when a typical decoder is implemented, a decoder corresponding to the lowest coding rate is implemented. In contrast, when a decoder is actually operated, in order to reduce consumed power, it is unnecessary to perform entire decoding by using a low coding rate, and thus, the size of a required HARQ buffer is increased.
Therefore, there is a need for various transmission techniques capable of obtaining a performance gain by adaptively changing a modulation parameter, a coding rate, and the like according to conditions of channels and resources.